In restrooms, workshops, laboratories, hospitals and similar places, there are many individuals who require access to cleaning soap. Providing soap and detergent bars for multiple use poses a problem because some individuals dislike using a soap bar which had been used before by a person who may have left a wet, soggy soap bar. To obviate this problem to a degree, powdered soap dispensers have been provided. However, the dispensing of powders and pastes, if very viscous, is at an extremely slow rate, if at all. Also, powdered soap may cake in the hands and require vigorous rubbing with water before it becomes solubilized and loses its grittiness.
Liquid soaps therefore have certain advantages over soap bars and powdered soap, because the liquid soap is already partially emulsified in a diluent resulting in quick further dispersal. Liquid soap dispensers are well known and have been used and widely installed in lavatories in public places, such as restaurants, schools, hospitals, trains, etc.
Prior art devices for dispensing liquid soap usually have a reservoir that must be filled from a larger supply container. The filling operation tends to be time-consuming and messy. Such dispensers are usually mounted to a wall, making some parts difficult to service or replace. Also, it is often difficult to feed the product directly into the dispenser container by pouring the liquid from a big supply tank because the dispenser is so close to the wall.
Furthermore, prior dispensers have been of relatively complex construction, frequently using a large number of parts, the assembly of which entails substantial labor. For example, some dispensers employ a complex pressuring system to dispense the soap. These devices result in mechanical difficulties and are subject to undue wear and fairly rapid breakdown. Some difficulties may also arise when screws must be loosened for the replacement of parts, particularly the dispensing nozzle or cartridge pump, which may become rusted and/or encrusted with the soap.
Liquid soap dispensers which are installed in restrooms, washrooms and the like are subject to damage by vandals. It therefore becomes necessary for the dispensers to be repaired or replaced on a periodic basis. When several dispensers must be replaced periodically, it results in a significant expense and inconvenience.
In some situations, it is necessary to make sure that a certain type of product is dispensed from a certain dispensing apparatus. For example, a plurality of dispensers may be used in a hospital for dispensing different types of soap or lotion products, or a restaurant may employ a plurality of dispensers for several types of condiments. Another example is a situation in which a company has installed a relatively expensive and durable dispensing device which is intended for use with a high quality soap product, and the company wishes to prevent use of the dispenser with a lower quality soap product. With prior dispensers, there has been no mechanism to prevent the dispensing device from being filled with the improper type of product, when the dispensing device is meant to be dedicated to a certain type of product.
Some prior soap dispensers utilize a container or cartridge of liquid soap which is removably mounted on a dispensing apparatus so that it can be replaced by another cartridge when it is empty. However, the soap containers for some such dispensers are of the refillable type. This means that the spent containers must be collected, sterilized, refilled and sealed for reuse, which is a time-consuming and expensive operation. Because the container is refillable, the refill opening is accessible to users. This could result in contamination of the contents or refilling with soap from an unauthorized source.
In some dispensers, the container is readily removable from the dispenser by any user, so that the entire container could easily be replaced by a "bootleg" container. To avoid this problem, some dispensers are provided with closed, lockable cabinets for enclosing the refill cartridge or container, so as to prevent access by unauthorized persons. But this type of housing is relatively expensive. Furthermore, such prior dispensers have had a relatively complex construction, frequently using a large number of parts, the assembly of which entails substantial labor.
The prior art dispensers have exhibited one or more other disadvantages. Such disadvantages include the need for substantial pressure to expel the liquid, difficulty in replacing the liquid reservoir, liquid dripping, the opportunity for bacterial contamination, the potential for entrapping air, difficulty in varying the volume of delivered liquid, inability to substantially empty the liquid reservoir, and the like.
The present invention solves many of the problems associated with currently available dispensers.